Adds support for GPON SFP modules based on the Realtek RTL8672 and
RTL9601C chips, including but not limited to:
* V-SOL V2801F
* C-Data FD511GX-RM0
* OPTON GP801R
* BAUDCOM BD-1234-SFM
* CPGOS03-0490 v2.0
* Ubiquiti U-Fiber Instant
* EXOT EGS1
Signed-off-by: Vladimir Markovets <abam_a@yahoo.com>
(cherry picked from commit f032601ed7)
